• Journal of Korean Institute of Industrial Engineers
• /
• v.31 no.1
• /
• pp.36-43
• /
• 2005

It is the basic requirement of design process of parts assembly to specify geometric dimensions and tolerances of product characteristics. Among them, tolerance stack analysis is one of the important methods to specify tolerance zone. Tolerance stack analysis is to calculate gap using tolerances which includes geometric and coordinate dimensions. In this study, we suggested more general method called the virtual method to analyze tolerance stack. In virtual method, tolerance zone is formed by combination of dimensional tolerance, geometric tolerance and bonus tolerance. Also tolerance zone is classified by virtual boundary condition and resultant boundary condition. So gap can be defined by combination of virtual boundary and/or resultant boundary. Several examples are used to show the effectiveness of new method comparing to other methods.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.4
• /
• pp.197-202
• /
• 2001

This paper proposes a design method for improving the disassembly by using the axiomatic approach. A product developer must design disassembly as well as assembly when designing the structure of a product. Axiomatic approach is a design tool that optimizes design. In this paper design evaluation method using information axiom sets impact variables and value function. As a result, examining the relationship between the functional requirements and evaluating the information can optimize designs.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.171-174
• /
• 2007

During last 30 years, Korea economy has grown so fast and many leading-edge technologies ware introduced from the advanced countries. but this fast growth inevitably produced imperfect completion of infrastructures and caused man-made catastrophes like Sungsu Bridge and Sampoong Department Store. After the incidents, Korea Government and National Assembly established "The Special Law for Safety Maintenance of Infrastructures". According to this law, most of infrastructures must be inspected periodically. During last 10 years after the establishment of the law, many infrastructures were improved and the quality of construction was upgraded. However, important and weak-to-disaster infrastructures need to be watched continuously. Many monitoring technologies were developed and tested in the field. In this paper, the new research project "Establishment of Testbed of Safety Management Network for Main Infrastructures", funded by government, was introduced.

• International Journal of Automotive Technology
• /
• v.8 no.6
• /
• pp.713-722
• /
• 2007

Design variables for suspension systems cannot always be realized in the actual suspension systems due to tolerances in manufacturing and assembly processes. In order to deal with these tolerances, design variables associated with kinematic configuration and compliance characteristics of suspensions are treated as random variables. The reliability of a design target with respect to a design variable is defined as the probability that the design target is in the acceptable design range for all possible values of the design variable. To compute reliability, the limit state, which is the boundary between the acceptable and unacceptable design, is expressed mathematically by a limit state function with value greater than 0 for acceptable design, and less than 0 for unacceptable design. Through reliability analysis, the acceptable range of design variables that satisfy a reliability target is specified. Furthermore, through sensitivity analysis, a general procedure for optimization of the design target with respect to the design variables has been established.

• Journal of the Korean Society of Safety
• /
• v.25 no.5
• /
• pp.7-14
• /
• 2010

Ultra high pressure system, which can be generally increased over 1,000bar, needs to have sealing mechanism to protect leakage and selection of the materials used in the intensifier. Components such as pressure vessel, hydraulic hose assembly, accumulator, hydraulic cylinder, hydraulic valve, pipe, etc., are tested under the impulse-pressure conditions. Components need to be tested under 1.5 to 3 times of rated pressure to check the tolerance even though rated pressure range of these components are not ultra high pressure. So, the ultra high pressure system needs to be equiped to test components. In this study, safety assessments of ultra high pressure system which are using failure analysis of components, changing the types of the control system, and finite element analysis with static condition, are investigated.

• Journal of Korean Library and Information Science Society
• /
• v.36 no.1
• /
• pp.117-130
• /
• 2005

This study is to examine the research trends of bibliotherapy in Korea through an analysis of databases(monograph, master's and doctor's dissertations, and journal articles) in National Assembly Library and to analyze the citations and documents in various aspects(year, field, object, pattern) . The study is to present basic data for bibliotherapist and researcher and to indicate the direction of their study in the future.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.50 no.5
• /
• pp.605-615
• /
• 2017

A multi-resonant broadband acoustic transducer with six Tonpilz elements operating at different resonant frequencies in a transducer assembly was fabricated, tested, and analyzed. A compensated transducer, modified by adding series inductance to the developed multi-resonant broadband transducer, was shown to provide improved bandwidth performance with a relatively more uniform frequency response compared with the uncompensated transducer. By controlling the series inductance, flat frequency response characteristics at two frequency bands were obtained over the range 38-52 kHz with 1.1 mH inductance and 50-60 kHz with 0.4 mH inductance. These results suggest that the operating frequency of the developed multi-resonant broadband transducer in a chirp echo sounder can be shifted to a different frequency band that is optimized according to the environment for more effective echo surveys of fishing grounds.

• Nuclear Engineering and Technology
• /
• v.41 no.8
• /
• pp.995-1004
• /
• 2009

The Advanced Power Reactor 1400 (APR1400) is an evolutionary advanced light water reactor (ALWR) based on the Optimized Power Reactor 1000 (OPR1000), which is in operation in Korea. The APR1400 incorporates a variety of engineering improvements and operational experience to enhance safety, economics, and reliability. The advanced design features and improvements of the APR1400 design include a pilot operated safety relief valve (POSRV), a four-train safety injection system with direct vessel injection (DVI), a fluidic device (FD) in the safety injection tank, an in-containment refueling water storage tank (IRWST), an external reactor vessel cooling system, and an integrated head assembly (IHA). Development of the APR1400 started in 1992 and continued for ten years. The APR1400 design received design certification from the Korean nuclear regulatory body in May of2002. Currently, two construction projects for the APR1400 are in progress in Korea.

• Journal of Auto-vehicle Safety Association
• /
• v.7 no.4
• /
• pp.31-38
• /
• 2015

In the United States, when NHTSA initiates the vehicle defect investigation, the most of automotive manufactures voluntary start their vehicle's recall campaign immediately. However, in the domestic market, NGOs, medias and even the National Assembly complaint the attitude of domestic and foreign makers tendencies of retardation of recall campaign. Also there were criticism for the manufacturer's concealing or downsize of their vehicle defects to the publics. In general, the manufactures may wait until MLIT's decision to recall orders. Therefore, in this study, from the survey of foreign countries legal recall systems and it is recommended reinforcement of the current vehicle management law to promote more frequent voluntary recall campaign from makers. In this study, it is also includes summarize all previous recall related research works and proposes the more stringent regulations to punish of concealing or downsize their vehicle safety defects.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.7 no.1
• /
• pp.263-292
• /
• 1994

The purpose of this study is to investigate of differences on the viewpoint of value, job aspiration, job attitude between male and female librarians. The objects of survey are 60 librarians at National Assembly Library. The results of the survey are as follows 1) In general, librarians have advanced propensity on viewpoint of value. But female librarians appear more traditional propensity than male librarians 2) Generally, the ranking of core factors in job aspiration appears ① realise professional value, ② self confidence in occupation, ③ recognized by specialist. On this, female librarians come out ① self confidence in occupation ② realise professional value, ③ recognized by specialist. 3) Generally, librarians appear more conservative attitude than male librarians about indirect service in library